Transferring sterile material, such as biological liquids (blood, blood products, sterile liquids to be infused, medicines etc) between different containers, is subject to the categorical requirement that sterility has to be maintained during the whole transfer process.
Government requirements with respect to sterility can be summarized as follows: The sterile process shall be functionally equivalent to a “closed system” even though the process may be that of a “connected system”. The present innovation addresses this challenge and its technical solutions have been chosen to achieve the sterile standard provided by a “closed system”.
One application in which the invention may be used is in handling separated blood components. When the blood component has been separated, it is normally stored for a specific time period until it can be used for transfusion. The blood component must be preserved during this time period. After the storage and before transfusion, the blood component is often exposed to virus inactivation, in order to reduce or even eliminate the risk of virus infection. Such virus inactivation involves adding to the blood component a virus inactivation agent or liquid. Such addition of virus inactivation agent may take place before the storage or shortly before transfusion. In order to add such components, a sterile coupling is required.
Modern blood banks have a need for cost effective procedures and machines when preparing blood components in a safe and effective manner. One application is in the inactivation of virus and/or pathogens in cellular blood products such as red cell and platelet preparations. Currently, virus and pathogen inactivation entails adding photo-activated materials and exposure of the suspension to light of a suitable wave length, often ultra violet light for a given time interval. Future probable frequent use of these inactivation procedures point to the need of a sterile coupling which is simple, flexible and inexpensive.
A sterile coupling, which may be used in the above applications and similar applications is disclosed in DE 41 22 476. The coupling comprises mating male and female connectors, which are closed off from the surrounding atmosphere by each a rubber membrane and sterilized. When the connectors should be interconnected, the rubber membranes are brought into contact with each other and the membrane of the female connector is exposed to a force so that it ruptures and allows the entering of the male connector. Then the rubber membrane of the male connector reaches a protrusion, which tensions the membrane until it ruptures, thereby exposing the female connector to the male connector for interconnection. This coupling is relatively well protected from contamination but does not reach the standards which the present invention aims to. Thus, normal air comprises thousands of bacteria per liter air, which are attached to particles “floating” in the air. Such particles always adhere to surfaces exposed to such air. Thus, any external surface is contaminated and must not come into contact with an area which is to be maintained sterile.
The connector according to DE 41 22 476 is also provided with an air relief channel including a sterile filter. Such a sterile filter is always a risk factor.